# import numpy as np
# a1 = np.zeros(2)
# print('一维数组a1:\n',a1)
# a2 = np.zeros((2,3))
# print('二维数组a2:\n',a2)
# a3 = np.ones(3)
# print('一维数组a3:\n',a3)
# a4 = np.ones((3,3))
# print('二维数组a4:\n',a4)
# a5 = np.empty(4)
# print('一维数组a5:\n',a5)
# a6 = np.empty((3,4),dtype='int')
# print('二维整型数组a6:\n',a6)

#练习
import numpy as np
a7 = np.ones((2,3))*5
print('一维数组a7:\n',a7)